1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
lara [203]
3 years ago
8

A string is wrapped several times around the rim of a small hoop with radius 7cm and mass 2kg. The free end of the string is hel

d in place and the hoop is released from rest.
After the hoop has descended 80cm, calculate (a) the angular speed of the hoop and (b) the speed of its center.
Physics
1 answer:
Ivanshal [37]3 years ago
3 0

Answer:

Explanation:

Given that,

The radius of loop r = 7cm = 0.07m

Mass of hoop M = 2kg

The hoop is released from rest, the initial velocity is 0m/s

A. Angular speed of the hoop after a descended of h= 80cm = 0.8m

Applying the conservation of energy

Ei + W = Ef

Where,

Ei = initial energy of the system, I.e the initial potential and kinetic energy

Ef = final energy of the system I.e the final potential and kinetic energy

W = 0, since no external force is acting on the systems

Ui + K.Ei + 0 = Uf + K.Ef

System was initially at rest, K.Ei = 0

Uf = 0 at the zero level

Then,

Mgh = ½ •Icm•w² + ½M•Vcm²

Icm = Mr², since it is circular loop

Then,

Mgh = ½ •Mr²•w² + ½M•Vcm²

M cancels out

gh = ½ •r²•w² + ½ Vcm²

Since Vcm = wr

Then, gh = ½ •r²•w² + ½ w²r²

gh = r²w²

w = √(gh/r²)

w = √(9.81 × 0.8/0.07²)

w = 40 rad/s

b. Speed at the center

Since Vcm = wr

Vcm = 40×0.07

Vcm = 2.8 m/s

You might be interested in
a solution made by dissolving 116 g of CaCl2 in 64 g of water has a density of 1.180 g/ml at 20 degrees celsius what is the mola
Makovka662 [10]

Answer:

The molarity of CaCl2 in the solution is 4.94 M

Explanation:

First of all you need to calculate CaCl2 mass.

You have one atom of Ca = 40.07 g/mol and two atoms of Cl = 35.45 g/mol so the molecule has a mass of 110.97 g/mol.

Now, knowing that your solution will have a mass of 64 grams of water + 116 grams of CaCl2 = 180 grams, you can calculate its volume, knowing that density = mass/volume

density x mass = volume --> 1,180 g/ml x 180 g = 212.4 ml

In 212.4 ml, you have 116 grams of CaCl2. You can calculate how many moles of CaCl2 you have:

110.97 g ------ 1 mol

116 g -------- x = (116 g x 1 mol) / 110.97 g =  1.05 moles

The molarity in a solution equals how many moles of a certain solute you have in 1000 ml of solution. In this solution, you have 1.05 moles in 212.4 ml, so in 1000 ml you will have:

212.4 ml ------- 1.05 moles

1000 ml -------- x = (1000 ml x 1.05 moles) / 212.4 ml = 4.94 moles.

This means the molarity of CaCl2 in the solution is 4.94 M.

4 0
3 years ago
What is wrong with the following statement: When you exert a force on a baseball, the equal and opposite force on the ball balan
gregori [183]

Answer:

When you exert a force on a baseball, there exists an equal and opposite force on the ball therefore, the ball will accelerate in opposite direction.

Explanation:

When you hit a ball with baseball bat, the bat exerts a great force on the ball which causes the ball to accelerate in the opposite direction. It is to be noted that the mass of bat is much greater than mass of ball but the acceleration of ball is also greater than the acceleration of the bat so both bat and ball almost exert same magnitude of force but in opposite direction and as a result both bat and ball accelerate in opposite direction, the deciding factor is of course the relative force applied by the batter and the bowler.

6 0
3 years ago
A rock from space in Earth's Atmosphere would be considered?
Gnesinka [82]

Answer:

A meteor mate

Explanation:

hope this helps

8 0
3 years ago
Explain the principles of effective team
steposvetlana [31]

Answer:

work relationship built on trust.

Explanation:

Align on a set of communication best practices understood by all members of the team. Create a work environment built on trust and empathy. Manage healthy conflict through standards, processes, and real-time feedback. Develop a support system through patience and discipline.

5 0
3 years ago
What is scientific inquiry (method) ?
Shtirlitz [24]
A method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses
6 0
3 years ago
Other questions:
  • Why do we dream? hurry plz
    6·2 answers
  • Relative to the distance of an object in front of a plane mirror, how far behind the mirror is the image?
    7·1 answer
  • If an equation is dimensionally correct, does this mean that the equation must be true? If an equation is not dimensionally corr
    11·1 answer
  • You are given a long length of string and an oscillator that can shake one end of the string at any desired freqeuency
    6·1 answer
  • The number that describes the main energy level of an electron in an atom is
    15·1 answer
  • NEVERMIN I've got it. :D
    15·1 answer
  • Wildlife biologists are attempting to monitor the population size of the insect pest known as the gypsy moth (Lymantria dispar)
    12·2 answers
  • What type of magnetism is present in a bar magnet?
    11·2 answers
  • Suppose you hit a 0.058-kg tennis ball so that the ball then moves with an acceleration of 10 m/s2. If you were to hit a basketb
    9·2 answers
  • Which identifies the energy transformations that take place in Anna’s body as this process takes place?
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!